Apparatus for production of fine glass fibers



1966 .1. STEPHENS ETAL 3,233,992

APPARATUS FOR PRODUCTION OF FINE GLASS FIBERS Original Filed May I., 1959 3 Sheets-Sheet 1 INVENTORS. dafija/r E 52%; fie/w F Feb. 8, 1966 J. F. STEPHENS ETAL 3,233,992

APPARATUS FOR PRODUCTION OF FINE GLASS FIBERS 3 Sheets-Sheet 2 Original Filed May l Feb. 8, 1966 .1. F. STEPHENS ETAL 3,233,992

APPARATUS FOR PRODUCTION OF FINE GLASS FIBERS Original Filed May 1, 1959 3 Sheets-Sheet 5 INVENTORS.

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United States Patent 3,233,992 APPARATUS FOR PRODUUIION OF FINE GLASS FIBERS Joseph F. Stephens, Kansas City, Mo., and Frederick N. Stephens, Leawood, Kaus., assignors to Gustin-Bacon Manufacturing Company, a corporation of Delaware Original application May 1, 1959, Ser. No. 810,283. Divided and this application Dec. 28, 1961, Ser. No. 162,777

4 Claims. (Cl. 65--15) This application is a divisional application carved out of our pending application Serial No. 810,283, filed May 1, 1959, now abandoned, entitled, Method and Apparatus for Production of Fine Glass Fibers.

This invention relates to methods of and apparatus for producing fine glass fibers and refers more particularly to such methods and apparatus wherein a continuous feed stream of molten glass is divided into a plurality of small diameter flows distributed from the periphery of a high speed rotating device into the path of a high temperature gas blast to achieve attenuation of the glass flows and commercially produce at a high rate glass fibers of a diameter from one to five microns.

Previously, certain methodsand apparatus have been provided by the art in an elfort to continuously and commercially produce fine diameter glass fibers by the centrifugal projection of molten glass streams into a high velocity, high temperature attenuating gas blast. A number of critical problems, however, have been raised by the development of such processes which have not been solved by the art. Very extreme environmental conditions exist in such processes, wherein, for example, 1900 F, molten glass is fed into a body rotating at a rate of from three to four thousand revolutions per minute with a burning gas blast passing immediately peripherally of the rotating body of a temperature of approximately 3000 F.

The limited strength and endurance of materials available to fabricate apparatus for practicing such processes make it necessary to rigorously shield and protect key portions of the apparatus from excessive heat whereby to permit continuous operation and substantially long life. Means additionally must be provided to protect the rotating body against unbalance caused by change or movement of the glass feed stream thereto. Means must be provided to permit regulation of the gas blast motion and position relative the rotating body to obtain optimum attenuation of the fibers. It would be desirable also to be able to control the character of the gas blast flame to better control the fiber attenuation.

Therefore, an object of the invention is to provide methods of and apparatus for the production of fine glass fibers which are capable of continuous operation and wherein the apparatus has a sufiiciently long operating life to permit commercial production of fine glass fibers which are capable of continuous operation and wherein the apparatus has a sufficiently long operating life to permit commercial production of fine glass fibers at high rate.

Another object of the invention is to provide methods of and apparatus for the production of fine glass fibers wherein molten glass is fed in a continuous stream to a rotating fiber-forming device moving at a very high rotational velocity, the fiber-forming device so formed that even substantial wavering and/or discontinuities of the feed stream of glass are compensated for and do not imbalance the device or interfere with the fiber-forming operation and apparatus.

Another object of the invention is to provide methods of and apparatus for production of fine glass fibers where- 3,233,992 Patented Feb. 8, 1966 "ice in a perforated rotor is spun at high rotational velocity to distribute fine filaments of glass therefrom, a molten stream of glass passing centrally of the means applying rotational force to the rotor and a continuous blast of high temperature gas being directed immediately peripherally of the rotor, both the glass and gas flows acting to apply weakening heat stress to the means driving the rotor, means being provided to so minimize such heat stress as to permit substantially continuous operation and long life of the apparatus.

Another object of the invention is to provide methods of and apparatus for production of fine glass fibers Wherein the location of the gas blast relative the fiber-forming area peripheral to the fiber-forming device is adjustable to obtain optimum fiber attenuation.

Yet another object of the invention is to provide methods of and apparatus for production of fine glass fibers wherein the gas blast peripheral to the fiber-forming device may be regulated to always provide an oxidizing fiame whereby to insure maximum fiber attenuation, if desired.

Another object of the invention is to provide methods of and apparatus for production of fine glass fibers wherein a continuous homogeneous gas blast is provided in a ring peripheral to a fiber-forming rotor, the blast itself rotating at high velocity relative its emission area without resort to directing means or jets whereby to permit such control of the blast and effect on the fibers as to obtain optimum and uniform fiber attenuation.

Still another object of the invention is to provide apparatus for production of fine glass fibers including a perforated rotor, means for spinning said rotor at a very high velocity, means for transferring a molten stream of glass through the rotor in a uniform fiow and means for providing a rotating continuous gas blast closely peripheral to the rotor, said apparatus being of minimum complexity, having its critical parts readily accessible for replacement and/or repair, said apparatus of relative ease of manufacture and relative minimum expense, yet having long life and great endurance under the extreme environmental conditions of operation and operable to produce fine glass fibers of commercial quality at a high rate.

Other and further objects of the invention will appear in the course of the following description thereof.

In the drawings, which form a part of the instant specification and are to be read in conjunction therewith, an embodiment of the invention is shown and, in the vari ous views, like numerals are employed to indicate like parts.

FIG. 1 is a top view of an apparatus embodying the invention with parts cut away and in section to better illustrate the inventive structure.

FIG. 2 is a side partly sectional view with parts out cut away to better illustrate the inventive structure of the apparatus embodying the invention of FIG. 1.

FIG. 3 is a simplified view taken along the line 3-3 of FIG. 2 in the direction of the arrows with some parts omitted for clarity.

FIG. 4 is a side, partly cut away sectional view of the inventive fiber-producing rotor employed in the inventive apparatus and method.

FIG. 5 is a fragmentary plan view of a modification of the replaceable orifice rings defining the firing chamber orifice with openings shown extending through the outer ring to permit entrainment of air with the gases passing through the orifice.

FIG. 6 is a view taken along the line 66 of FIG. 5 in the direction of the arrows.

Referring to the drawings, and more particularly to FIGS. 1, 2 and 3, at 20 is shown a cylindrical support 31', casting having inwardly extending upper and lower ring portions 21 and 22. The outer race 23 of a ball bearing is rigidly fixed relative ring 21 by jaw members 24 and 25 fixed to ring 21 bybolts 26. The outer race 27. of

a second ball bearing is welded or otherwise fixedly attached to theinner face of ring 22. Cylindrical torque .1

tube 28 has fixed to the outer surface thereof the inner races 29 and 30 of the ball bearings tomatch outer races 23 and 27, respectively. Torque tube 28 extends substantially below ring 22 of casting 20 and has aninternally threadedmember 31 .fixed interiorly of its lower end.

Means for driving the torque tube in high speed rotation relative the support casting on the bearings previously described are mounted on the casting 20 and connect to the torque tube. Belt ring 32, having circumferential groove 33 formed therein to receive conventional friction belt 34, is welded or otherwise fixedly attached to the outer surface of torque tube28 intermediate of races 29 and 30. Theother end of belt 34 fits over pulley 35 which is fixedly attached to shaft 36. Shaft 36 is driven in high speed rotation by conventional electric motor 37 or other prime mover fixedly attached to plate 38 by bolts 39. Plate 38 is pivotally mounted on ears 40 on casting 20 by pin 41. Adjustable bolts 42 thread through openings (not-shown) in plate 38 and abutplatforms '43 on casting 20. Lock nuts 44serve prise mounting plate .46 fixedly attached to casting 20 r by bolts 47 engaging openings 47a in the upper end of the casting. Dividers a space the inner and outer concentric walls of tube 45 from one another to permit .heat exchanging liquids such. as water or other suitable medium to pass therebetween. Input flow line 49 and-outputflow A line 48 (FIG. 1) pass heat exchanging liquid to and from the annulus between the inner and outer walls of tube 45.

Tube 45 preferably extends within torque tube 28 substantially the entire length thereof closely adjacent .to internally threaded member 31. The upper and lower ends of tube 45 are closed by'plate 46 and ring 45b, respectively.

Means for providing a burning gas blast are mounted on casting 20. Gas inlet flow line 50 leads into ring. manifold 51 circumferentially positioned relative to.

torque tube 28. The enclosing walls 52a, 52b, 52c and 52d of manifold 51 are rigidly fixed to one another and the lower portion of casting 20. A plurality of gas flow lines 53a, 53b, 53c and 53d lead fromopenings in the upper wall 52a of manifold .51 outwardly, downwardly and into tangential inlet ports 54a54d,.inclusive. Tangential inlet ports 54a54d, inclusive, lead into ring com- This means com-.

bustion chamber 55 through perforated fire screens 56a, 2

gases flowing in the ports will move in a circular direc- I tionin the'combustion chamber 55. A continuous ring gap is provided between'the inner and lower refractoryrings. 62 and 63 whereby to provide a continuous circumferential outlet orifice for the combustion gases.

The lower .Wall 52c of the manifold 51 and the upper wall 57 of the combustion chamber provide'itherebetween a ring-shaped space or volume 66 adapted to receive heat ring space 68 adapted to receive 'heatexchanging medium. Suitable ring members 69 and 70 seal the upper and lower limits of the space .68 and are attachedto walls 67 and 58 by welding or other. conventional means. Lower, horizontally disposed ring wall 71 having'ring cavity 72 formed therein provides, with lower wall 59 of the combustion chamber 55, yet a thirdvolume for the receipt; of heat exchanging medium such as water. The connections to theheat exchanging medium receiving spaces 66, 68 and 72 are notzshown for the sake of simplicity but are of the same character as input and;

output flow lines. 48 and 49. The entire combustion chamber'assembly, including the. walls surrounding heat exchanging medium spaces, refractories, combustion chamber walls, etc". are rigidly fixed to. one another and. the lowerrwall 52'cof manifold 51- andthus rigidly con-i nected to the casting 20. 1

by a ring clip 73a 'withjbolts 73b engagingboth the clip 73a and {the flange 73 ;to tightly fix'them'against the lower. outside edge of :the combustion chamber assembly.

Inner and outer orifice; rings 74 and ;75 .are fixed by bolts 76 and .77 to rings 70 and.71,.respectively. Ori-; fice rings 74 and 75 :are removable to. permitadjustment oftorque tube 28. Referring to FIGS. 2 and. 4, the rotor may be generally. designated as 80 and has a .top wall 80a,

a side wall 80b and a bottom 'wall 800. Side wall 80b iSE oriented substantially parallel to the axis of tube 28 and comprises" a ring. of suitable .metal able to-withstand the temperature: .of molten glass andthe adjacent gas blast and has a plurality of openings'or perforations 81 extending therethrough. Perforations 81 are preferably arranged in parallel rows extending circumferentially around the .wall 80b; Upperwall 80a isdished upwardly from its connection with wall 8% centrally thereof-and has. opening -82 aso :centrally thereofi- Externallylthreaded cylindrical member '83 is Welded or otherwise fixedly attached to the top wall 80a sothe opening'82 is continuous Wltlllthe .inside' of'member 83. 7 Bottom wall 80c isdished centrally from'its connection with sidewall 80b and has cup-shaped depression 84 centrally thereof'below.

opening 82. Depression 84is circular in plan view and 1n any vertical cross section forms an are of a circle. The

diameterof the depression 84' at the top thereof is pref-.

erably at least substantiallythe inside? diameter of water tube 45. A nut.85, hexagonal in shape to aid in attaching. the :rotor to torque tube 28, isfixedly attachedto the under: side of the wall of depression84z With rotor .80 threaded to member 31,; flange; '73 preferably extends. substantially below the lower end of the rotor and nut 85;.

The sidewall 80]) of rotor fitl is preferably a ring such as that disclosed in the application of JosephTLWarkoczewski,filed 'iMarch r14, 1958, Serial No. 721,491,

Method and Apparatus -for. Forming Finely Perforated.

Rings, now Patent'No. 3,040,898, and'may befabricated by such a method as is disclosed in said application. The

metal forming the upper and lower walls of the rotor may be formed of an alloy similar to that employed to form the side wall 80b as disclosed in the Warkoczewski application, supra.

As there is a gap required between the top of the rotor 80 and the inner ring 74, a ring 86 is fixed to the inside surface of wall 67 immediately above the top of the rotor and has its inner surface as closely adjacent the outer surface of the spinning torque tube as possible. Ring 86 prevents the migration of burning combustion gases upwardly along the outer surface of the torque tube 28.

In the operation of the inventive apparatus and method, assuming the apparatus assembled as in FIG. 2 with a rotor fixedly threaded on torque tube 28, a conventional source (not shown) of a single feed stream of glass being positioned above the torque tube 28 and water tube 45, such as a platinum bushing with a single orifice therein, the orifice centrally positioned above the tubes mentioned, a conventional source of gas connected to inlet flow line 50, and heat exchanging medium flowing through water tube and spaces 66, 68 and 72, warming-up preparation for operation of the device and practice of the method may begin. Rotation of torque tube 28 with attached rotor 80 by belt 34 driven by motor 37 is commenced.

A regulated gas-air mixture of proper combustion ratio to give the temperature desired is flowed in through line to manifold 51 from whence the mixture passes through flow lines 53a, 53b, 53c and 53d to tangential inlet ports 54a, 54b, 54c and 54d. The combustion gases swirl around the combustion chamber 55 at a high velocity with a ring-shaped blast of gas passing downwardly through the continuous circular orifice 78 peripheral of the rotor. This blast, once established, is ignited, whereby to provide a continuous circular ring of burning gases surrounding the periphery of the rotor with the gases moving both downwardly out of combustion chamber 55 and in a circular direction following their path in the combustion chamber. The direction of rotation of the gases must be in the same direction as the direction of rotation of rotor 80, if relatively long fibers are desired. Rings 74 and 75 forming the orifice 78 are removable to permit relocation of the orifice position as desired relative the periphery of the rotor. Thus the position of the flaming ring of burning gas may also be adjusted to the desired position relative the periphery of the rotor. It is preferred that the flames do not actually contact the side wall 801: of the rotor, but pass very closely adjacent thereto whereby to maintain the side Wall 8017 at a greater temperature than the temperature of the rotor interiorly thereof.

The quantity of gas flowed into the tangential inlet ports 5411-5451, inclusive, is preferably suflicient to move the gases in a circular direction in the chamber 55 and flowing therefrom at a velocity substantially that of rotation of the rotor 80.

When the rotor has reached the desired temperature, a process which may take a substantial period, as from 15 minutes to an hour, a gravity flow of molten glass in a continuous stream downwardly centrally of the water tube 45 is commenced from the source of glass which may be a conventional refractory furnace connected to a one-orifice platinum bushing. The stream of glass falls continuously from the bushing centrally of the tubes 45 and 28 without contacting the walls thereof. As the water tube 45 extends down substantially to the top of member 31, the inner surface of torque tube 28 and the bearings are substantially fully protected from the radiant heat of the glass stream. The glass stream falls into the depression 84 of the rotor 84), forming a pool from which glass is moved peripherally of the rotor by centrifugal force. The quantity of glass flowed into the rotor 80 must be regulated to the amount passed out of the orifices 81 in side wall 80b. Depression 34 compensates for any wavering or inconsistencies in the stream of glass whereby to provide an even feed of glass to the side wall and prevent rotor unbalance, whether or not the stream of glass falls precisely centrally of the bottom wall 800 of the rotor. As the outwardly flowing glass from depression 84 moves up the side wall 80b, it is forced outwardly by centrifugal force through the openings 81 in a plurality of small diameter molten streams. As the streams issue from the outer face of the side wall 801;, they trail the rotor in a direction opposite the direction of rotation thereof. The motion of the gas blast through the orifice 78 (which strikes and attenuates the stream) in the direction of rotation of the rotor tends to compensate for the fiber trailing, permits formation of longer fibers, minimizes fiber winding, and thus improves the product. The uniform, homogeneous character of the gas blast through the continuous circular orifice acts substantially uniformly on all of the streams and thus also provides a more uniform product.

The continuous orifice 78 permits both the movement of the gas blast in the direction of rotation of the rotor and a uniform effect of the blast on the fibers impossible without the homogeneous blast. Flange 73 serves both to guard against any particles which might fly tangentially from the rotor and also serves to aid in directing the fibers in a downward direction as they separate from the continuous streams issuing from the orifices 81. Ring 86 prevents the passage of burning gases thereabove and thus protects the outer surface of the torque tube 28 and the bearings above ring 86.

If openings 79 are provided in an outer ring a as shown in FlG. 5, an oxidizing blast may be insured, which, in many cases, may be desirable or necessary to obtain the quality and type of fiber desired. A typical rate of rotation of the rotor in the inventive process would be 4000 rpm. By the provision of the flame shield ring 86, it is possible to bring the gas blast in closer to the periphery of the rotor without obtaining excessive heating of the top portion of the rotor. Additionally, the rotor should be as closely spaced to the ring 74 as possible to minimize passage of combustion gases thereabove. Preferably, the side wall 8% of the rotor is maintained at a temperature higher than the input temperature of the glass which may be, for example, l800 to 1900 F. If the side wall 8% is maintained at approximately 2200 with the temperature of the gas blast next thereto at a yet greater temperature, cooling of the glass before blasting thereof after extrusion from the side wall 80b is avoided. This relationship is preferred.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are inherent to the methods and apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter hereinabove set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. A rotor for use in the production of fine glass fibers operable to be spun around a substantially vertical axis comprising a hollow, disc-shaped body having upper and lower and side walls, the upper wall having an opening centrally thereof for admitting a stream of molten material, means for detachably fixing said rotor to means for spinning said rotor fixed to the top wall circumferential to said opening, the side wall having a plurality of orifices extending therethrough along at least substantially its entire extent, the outer portion of the lower wall dished downwardly, and a separate circular arcuate retaining depression centrally formed in the lower wall of the rotor below said outer dished portion to form a surface discontinuity in said lower wall at the intersection of said depression ands'aid outer dished portion, said depression being in vertical alignment with and below the opening in the upper wall thereof for the reception and temporary retention and distribution of said stream of material admitted through said opening along said dished portion to the orifices of said side wall to stabilize said stream of material .thus to prevent unbalance of said rotor and to provide an even feed of material from said Well up said dished portion to said wall orifices.

2. A rotor as in claim 1 wherein the width of the depression is substantially that of the width of the opening into the upper wall.

3. A device for spinning heated thermoplastic material into fibers including in combination a top formed with an opening therein for the admission of a stream of said material, a side Wall formed withorifices through which said material is adapted to pass to form fibers, a base providing a generally concave internal surface leading .up to said side wall and a separate retaining well insaid base.

below the level of said concave surface to form a surface discontinuity in said base at the intersection of said well and said concave surface, said well disposed beneath and in vertical alignment with said openingtfor the reception and temporary retention and distribution of said stream1 of material admitted through said opening along said concave surface to the orifices of the side wall, said. well being generally symmetrical with respect to said axis of rotation to stabilize said stream of material thus to prevent unbalance of said rotor and .to provide an even feedof material from said well up said concave surface to said wall orifices.

4. An integral structure adapted to be secured to a rotating member to spin heated thermoplastic material.

V 8 into fibers including in. combination a jtopformedlwith an opening for the admission of a stream of said material,

a base, a side wall disposed between said top and said base, said base providing a generally concave internal surface leading up to said side wall, said sidewall being formed with orifices through which said material is adapted to pass to formfibers'ya separate retaining well in said base below the level of said concave surface to form a surface discontinuity insaid base at the intersection of said well and said'concave surface, saidwell-disposed below and in vertical alignment with said opening for receiving and temporarily retaining and uniformly distributing saidstream of material'admitted through said open- 'ing along said-concave surface to theorifices in the side wall, said well being generally symmetrical With respect to said axis of rotation to stabilize said stream of material thus'to prevent unbalance, of said rotor and to provide an even feed of material from said well. up said concave surface to said wall orifices, a sleeve surrounding said opening,'said sleeve being formed with threadsfor secur.-.

ing said structure to said rotating member and'a lllltOIl saidwell for tightening said structure on said rotating DONALL H.'SYLVESTER, Primary Examiner, 

1. A ROTOR FOR USE IN THE PRODUCTION OF FINE GLASS FIBERS OPERABLE TO BE SPUN AROUND A SUBSTANTIALLY VERTICAL AXIS COMPRISING A HOLLOW, DISC-SHAPED BODY HAVING UPPER AND LOWER AND SIDE WALLS, THE UPPER WALL HAVING AN OPENING CENTRALLY THEREOF FOR ADMITTING A STREAM OF MOLTEN MATERIAL, MEANS FOR DETACHABLY FIXING SAID ROTOR TO MEANS FOR SPINNING SAID ROTOR FIXED TO THE TOP WALL CIRCUMFERENTIAL TO SAID OPENING, THE SIDE WALL HAVING A PLURALITY OF ORIFICES EXTENDING THERETHROUGH ALONG AT LEAST SUBSTANTIALLY ITS ENTIRE EXTENT, THE OUTER PORTION OF THE LOWER WALL DISHED DOWNWARDLY, AND A SEPARATE CIRCULAR ARCUATE RETAINING DEPRESSION CENTRALLY FORMED IN THE LOWER WALL OF THE ROTOR BELOW SAID OUTER DISHED PORTION TO FORM A SURFACE DISCONTINUITY IN SAID LOWER WALL AT THE INTERSECTION OF SAID DEPRESSION AND SAID OUTER DISHED PORTION, SAID DEPRESSION BEING IN VERTICAL ALIGNMENT WITH AND BELOW THE OPENING IN THE UPPER WALL THEREOF FOR THE RECEPTION AND TEMPORARY RETENTION AND DISTRIBUTION OF SAID STREAM OF MATERIAL ADMITTED THROUGH SAID OPENING ALONG SAID DISHED PORTION TO THE ORIFICES OF SAID WALL TO STABILIZE SAID STREAM OF MATERIAL THUS TO PREVENT UNBALANCE OF SAID ROTOR AND TO PROVIDE AN EVEN FEED OF MATERIAL FROM SAID WELL UP SAID DISHED PORTION TO SAID WALL ORIFICES. 